The pop-up irrigation sprinkler of the present invention is of the same general type described in U.S. Pat. No. 4,220,283. Such pop-up sprinklers are generally well known to the art, and they are presently being manufactured by a number of different manufacturers.
The pop-up irrigation sprinkler referred to above includes a cylindrical body and a tubular riser positioned coaxially within the body. A nozzle is mounted on the upper end of the riser. The riser is normally spring-biased to a retracted position within the body. However, when water under pressure is introduced into the lower end of the body, the riser moves upwardly and extends through a cover at the upper end of the body to perform its sprinkling function.
The irrigation sprinklers described in the preceding paragraph usually include a filter for straining out particulate matter contained in the water. In the sprinkler of the invention as will be described, the filter is positioned at the top of the riser adjacent to the nozzle, and it is removably retained by the nozzle. With such an assembly, when the nozzle is removed from the riser, the filter also is removed since it is attached to the nozzle.
It is usual practice during the installation of a sprinkler system, and as a final step, for the installer to remove all the nozzles from the various sprinklers of the system, and to cycle pressurized water into the system. This water serves to flush out any dirt that might have accumulated in the pipes of the system when the system was being installed.
It is important that the filters be removed with the nozzles at this time, because if the filters are left in the sprinklers while the system is being flushed out, they will be blown out of the sprinklers and may be lost. The prior art sprinklers, for the most part, include filters which fit loosely into the assemblies, and they must be picked out with a screwdriver, wire or awl, after the nozzles have been removed, which is a tedious process, and also which has a tendency to damage the filters.
This necessity is obviated by the sprinklers of the present invention, since the filters come out with the nozzles when the nozzles are removed.
Another feature of the invention is to provide a sprinkler which includes an adapter fitted between the nozzle and the top of the riser. This adapter enables different types of nozzles manufactured by different manufacturers, and which may have different thread types and different lengths, to be used in the sprinkler. In all cases, as will be described, the adapter serves to trap the filter onto the nozzle.
Other features and advantages of the improved irrigation sprinkler of the present invention will become apparent from the following disclosure.